Final answer:
Louis de Broglie was a French physicist who proposed the wave-particle duality of matter. His theory stated that particles like electrons can exhibit wave-like behavior, which was a groundbreaking idea in the development of quantum mechanics.
Step-by-step explanation:
Louis de Broglie was a French physicist who proposed the wave-particle duality of matter. He extended the concept of wave-particle duality from light to material particles in his 1925 doctoral dissertation. De Broglie's theory stated that particles like electrons can exhibit wave-like behavior. His work was instrumental in the development of quantum mechanics, and he was awarded the Nobel Prize in Physics in 1929 for his contributions